Dr Ed Wallitt
Podmedics - Founder
Video Duration: 13 minutes
Serum sodium level < 135mmol/L
Varied pathology depending on fluid volume status and urinary sodium levels (high levels indicate a renal cause of hyponatraemia, whilst a low cause indicates an extra-renal cause)
Hypervolaemic hyponatraemia is often seen in patients with cardiac failure, liver cirrhosis or nephrotic syndrome, where there is a reduced ability of the kidneys to excrete water, leading to water retention and therefore dilution of serum sodium.
Depends on fluid balance/fluid volume as well as urinary sodium level.
Depends on serum sodium level (Mild/moderate/severe)
If serum sodium = 130-135mmol/L --> Asymptomatic
If serum sodium = 125-130mmol/L --> Nausea, vomiting, mild confusion
If serum sodium = 115-125mmol/L --> more pronounced confusion (due to cerebral oedema)
If serum sodium <115mmol/L --> convulsions, coma
If hypovolaemic --> vomiting, diarrhoea, use of excessive diuretics
If hypervolaemic --> h/o cardiac/liver/renal failure
Urine dipstick, for evidence of proteinuria, haematuria, glucosuria
Urinary sodium level
U&Es (to assess serum sodium level, renal function), with calculation of plasma osmolality
Urinary catheterization and record of fluid balance
Blood pressure measurements (sitting and standing)
Depends on fluid status.
Slow correction required to reduce the risk of Central Pontine Myelinolysis
In mild hyponatraemia
In mild cases of hypervolaemic hyponatraemia, treat with FLUID RESTRICTION and DIURETIC
In severe cases of hyponatraemia, consider use of DEMICLOCYCLINE if urinary sodium <125mmol/L or 3% SALINE (hypertonic solution); to be used under specialist guidance only!